FAQ: Colour Profiles and You

[DQE]

Now this is interesting! I did a test and it seems its not a photoshop/web colours issue, but rather theres a discrepancy between Irfanview and Photoshop!
I took an image, did a screen grab using Irfanview of the image when loaded into photoshop elements (PSE) and did another but grabbing the image when loaded into Irfanview, and theres quite a difference! So it would seem that my edition of Photoshop is adding something to the image!
]

Be sure and install the add-ins IrfanView needs to use raw images...

[DaveW]

I use Elements too, but you need the appropriate free down-loadable Adobe Camera Raw Converter plug-in for your camera Cyclops. However Adobe's marketing technique is to not make the latest Camera RAW Converter backwards compatible with older versions of Photoshop or Elements.

OK if the older version of Adobe Camera RAW covers your camera and is compatible with your software, but when you buy the latest camera you find the latest version of Adobe Camera Raw needed for it will not work with your old software.

I think we are up to Elements 8 now. The latest Adobe Camera RAW plug in covers all the previous cameras, plus the latest of course. Why it is not made backwards compatible I think is purely a marketing strategy to try and force software upgrading.

I use Elements 5 and luckily the RAW converter available for that covers my Nikon D200. You could search to see if your camera is covered by the Adobe Camera RAW plug-in for your version of Elements.

If you put your version of Elements and Adobe Camera RAW into your search engine you will find if a version is available that covers your software and camera.

RAW is not just for making prints Cyclops, you also use it for processing and sharpening images you post on the Web, including this site and then converting to JPEG's for posting. I never shoot JPEG's now, only RAW and just convert to JPEG's as the final stage.

http://www.luminous-landscape.com/essay ... uth1.shtml

http://www.luminous-landscape.com/tutor ... iles.shtml

Here is the Adobe Camera RAW plug-in conversion window in use in the Editor of my Elements 5.



RAW gives you much more control over the image than lossy formats like in camera JPEG's do which loose quality every time you re-save them.

I just use the output straight out of Elements using "Save for Web" Rik and they seem OK. Does "Save for Web" therefore both convert to JPEG and switch to the appropriate colour profile for the Web?

DaveW

[rjlittlefield]

Does "Save for Web" therefore both convert to JPEG and switch to the appropriate colour profile for the Web?

I suspect that varies depending on version.

What you describe is what seems sane to me.

However, I just now tested with Photoshop CS (Version 8.0), and that's not what it does. Instead, it just leaves the RGB values alone and strips the profile, leaving the browser no choice but to assume that it's sRGB and thus get the colors wrong. This strikes me as not sane. I have no idea why Adobe ever made that choice.

I hope that newer versions of Photoshop have fixed this problem, but I have not tested. My brand new CS5 is still in its box.

--Rik

[Cyclops]

Be sure and install the add-ins IrfanView needs to use raw images...

Woa, hang on, I didnt shoot in RAW here, I use JPEG fine. so whats causing this discrpancy?

[ChrisLilley]

See this URL for instructions on how to enable color/colour management in Firefox 3.

That article applies to Firefox 3.0 only.

3.1 enabled it by default.

Unfortunately 3.2 onwards (to current 3.6) changed the colour management library from a standard one to a crappy one Mozilla wrote themselves, so there is no ICC v.4 support and the v.2 support is buggy.

I don't use IE much but seem to recall that it doesn't handle color/colour management as fluently as Firefox 3.

IE up to version 8 has no colour management support *at all*. IE9, currently in developer preview, has full ICC v.2 and v.4 support.

So does Safari, on both Mac and Windows.

[ChrisLilley]

Now this is interesting! I did a test and it seems its not a photoshop/web colours issue, but rather theres a discrepancy between Irfanview and Photoshop!

The difference is that Irfanview (and many browsers, especially older ones) do not support ICC profiles while Photoshop does.

Edit: Iranview added ICC support in version 4.25

If your image editing tool has no menu options to set or change colour space - and it seems your version of Photoshop Elements does not - and if you are shooting JPEG anyway, then the simplest course of action is to go into the menus on your Canon DSLR and select sRGB colour space. Looks like you have it set to AdobeRGB.

[Charles Krebs]

Rik,

However, I just now tested with Photoshop CS (Version 8.0), and that's not what it does. Instead, it just leaves the RGB values alone and strips the profile, leaving the browser no choice but to assume that it's sRGB and thus get the colors wrong. This strikes me as not sane. I have no idea why Adobe ever made that choice.

In the "save for web" function:

In CS3 (V10), there is a "fly out" list that you get via the small arrow near the "preset" box. Then you can check off "convert to RGB"

In both CS4 (V11) and CS5 (V12) the check box for "convert to RGB" is clearly displayed (not buried in a "fly out" as in V10.

[Cyclops]

If your image editing tool has no menu options to set or change colour space - and it seems your version of Photoshop Elements does not - and if you are shooting JPEG anyway, then the simplest course of action is to go into the menus on your Canon DSLR and select sRGB colour space. Looks like you have it set to AdobeRGB.

Ah bingo!! It is indeed set to Adobe RGB in camera! Only thing is there's no sRGB setting! There's the following
Standard (would that be sRGB?)
Adobe RGB
Set 1
Set2
Set 3
Set Up

[ChrisLilley]

Ah bingo!! It is indeed set to Adobe RGB in camera! Only thing is there's no sRGB setting! There's the following
Standard (would that be sRGB?)
Adobe RGB
Set 1
Set2
Set 3
Set Up

If so its poorly labeled, but give it a try and see how it looks.

[DaveW]

According to this review on the Web for the 10D it says:-

"Sets color space: Standard = sRGB, Adobe RGB, or one of three custom parameter settings, Set 1, Set 2, or Set 3, which allow you to select Contrast, Sharpness, Saturation, and Color tone."

http://www.normankoren.com/EOS-10D_1A.html

DaveW

[Cyclops]

Thanks Dave! I shall have a tinker!

[DQE]

If your image editing tool has no menu options to set or change colour space - and it seems your version of Photoshop Elements does not - and if you are shooting JPEG anyway, then the simplest course of action is to go into the menus on your Canon DSLR and select sRGB colour space. Looks like you have it set to AdobeRGB.

Ah bingo!! It is indeed set to Adobe RGB in camera! Only thing is there's no sRGB setting! There's the following
Standard (would that be sRGB?)
Adobe RGB
Set 1
Set2
Set 3
Set Up

Just to be sure - these internal Canon image processing parameters only apply to photos output as jpegs. If you output and use raws, the parameters (other than the color space choice) do not apply.

Having said that, I recently read that Canon's image processing software (Digital Photo Professional aka DPP) now picks up these internal camera settings for things like contrast, color saturation and sharpness and it then applies them to raw photos automatically. If you use IrfanView or Photoshop you'll only have a straight, unmodified raw photo to work with.

Personally speaking, I prefer to have the unmodified raw photo be presented to me so I can see the photo before significant processing. I then decide what, if anything, to do to the photo. In Adobe Photoshop Bridge, I use built-in presets to perform common processing tasks, such as my default preferred amount of sharpening, etc.

Hope this helps. It sounds like you're working you way up the learning curve/ladder. After you've worked through a few batches of photos, you'll get used to the options and develop your own workflow. But first you have to develop a basic understanding of the involved issues and options!

[Cyclops]

Yea thanks. I do have a good photography knowledge base, been taking photos for over 30 years (oh no that makes me sound old!) But its the digital side of things; there are so many variables and incompatibility issues its unbelivable! And I'm still not sure why I need to use RAW when most of my images end up on a forum or at best on deviant art!

[rjlittlefield]

Personally speaking, I prefer to have the unmodified raw photo be presented to me so I can see the photo before significant processing.

I wonder what you mean when you say "unmodified raw photo".

To my mind there's no such thing, or at least no such thing that it would make sense to look at.

The image content of a raw file consists of unmodified sensor data, only one value for each pixel as seen through some color filter array. To turn this mess into RGB, with three values for each pixel and some reasonable appearance, requires a complicated interpolation algorithm that implicitly applies some amount of sharpening, almost always some amount of noise reduction, and certainly a conversion from sensor profile and color balance to some standard color profile. Regarding interpolation, Dave Coffin (author of dcraw) has a nice pithy description (HERE):

[interpolation] is a hard problem, easily defined:

1. Take a three-color RGB image. At each pixel, set two color values to zero.
2. Reconstruct the original three-color image as best you can from the remaining one color per pixel.

Dcraw currently gives a choice of four methods: Bilinear, Variable Number of Gradients (VNG), Patterned Pixel Grouping (PPG), and Adaptive Homogeneity-Directed (AHD).

At one time, Dave had a nice list of references to papers on raw interpolation algorithms. It was pretty interesting reading, though I got bogged down in the math.

Anyway, I'm concerned that those words "unmodified raw photo" represent a misleading concept. You can't have unmodified. The best you can hope is that the modifications are more or less "neutral", whatever that means.

--Rik

[Cyclops]

Ah I just remembered that the iamge example I posted,the spider,was taken with the Panasonic,which has no colour space settings available! It can shoot in TIFF instead of jpeg but I've not noticed any difference other than file size.